title: Are endothelial progenitor cells mobilized by myocardial ischemia or myocardial necrosis? A cardiac magnetic resonance study.
abstract: BACKGROUND
  In ST-elevation myocardial infarction (STEMI) patients, the main stimuli involved in endothelial progenitor cells (EPCs) mobilization are not fully understood. We aimed to assess by cardiac magnetic resonance (CMR) whether the extent of ischemic myocardium (area at risk (AAR)) or of necrotic myocardium (infarct size (IS)) can be correlated to levels of circulating EPCs.
  
  
  METHODS
  Peripheral EPCs were measured in fifteen STEMI patients at 24h after successful primary percutaneous coronary intervention (pPCI). Between two and four days after pPCI all patients underwent CMR assessment of myocardial AAR, IS, myocardial salvage (MS) and microvascular obstruction at late gadolinium enhancement CMR (LG-MVO).
  
  
  RESULTS
  CD34+/KDR+, CD34+/KDR+/CD45dim, CD34+/KDR+/CD45-, EPCs were related to extent of AAR (rho=0.51, p=0.05; rho=0.55, p=0.03; rho=0.72, p=0.002, respectively), while no relationships were detected with IS, MS or LG-MVO.
  
  
  CONCLUSIONS
  Our data show that EPCs were strongly correlated to extent of myocardial AAR, thus suggesting that progenitor cells mobilization in STEMI develops in response to myocardial ischemia and not to myocardial necrosis.
authors.affiliation: Department of Cardiovascular Medicine, Catholic University of the Sacred Heart, Largo A. Gemelli, 8, 00168 Rome, Italy. italo.porto@gmail.com
authors.forename: Italo
authors.initials: I
authors.lastname: Porto
authors.forename: Antonio Maria
authors.initials: AM
authors.lastname: Leone
authors.forename: Giovanni Luigi
authors.initials: GL
authors.lastname: De Maria
authors.forename: Christian
authors.initials: C
authors.lastname: Hamilton Craig
authors.forename: Alessandra
authors.initials: A
authors.lastname: Tritarelli
authors.forename: Claudia
authors.initials: C
authors.lastname: Camaioni
authors.forename: Luigi
authors.initials: L
authors.lastname: Natale
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Niccoli
authors.forename: Luigi M
authors.initials: LM
authors.lastname: Biasucci
authors.forename: Filippo
authors.initials: F
authors.lastname: Crea
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000379:methods; D018952:Antigens, CD34 / Q000096:biosynthesis; D042783:Endothelial Cells / Q000166:cytology*; D005260:Female; D005682:Gadolinium / Q000494:pharmacology; D006321:Heart / Q000503:physiopathology; D006801:Humans; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000473:pathology*; D009206:Myocardium / Q000473:pathology*; D009336:Necrosis; D011446:Prospective Studies; D012306:Risk; D013234:Stem Cells / Q000166:cytology*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000096:biosynthesis
chemical_list: D018952:Antigens, CD34; D005682:Gadolinium; D040301:Vascular Endothelial Growth Factor Receptor-2; D017493:Leukocyte Common Antigens